Excavations in Helgo, Sweden have uncovered numerous medieval artifacts that strongly suggest that the Vikings traveled and traded as far away as Northern India and Egypt.

Although the Egyptian artifact (a bronze ladle or scoop) is Coptic Christian rather than Islamic, and the Indian artifact is a statue of the Buddha, these artifacts show that the Vikings either traveled to or had access via trade routes to lands to the east, west, and north of Islamic lands during the Middle Ages. I think it is highly likely that some Vikings were aware of Islamic culture.